Native read GPIO pin function.

[pascalbythree]

Hey everybody, does anyody know how to convert this procedure to a read PIN function;

Code: Pascal  [Select][+][-]

1.     { Swith SoC pin 17 on: }
2.     gReturnCode := fpsystem('echo "1" > /sys/class/gpio/gpio17/value');
3.     LogMemo.Lines.Add(IntToStr(gReturnCode));

as seen in this wiki:

https://wiki.freepascal.org/Lazarus_on_Raspberry_Pi#Native_hardware_access

i want to use the fpsystem procedure and if you will take a closer look at te website, it is only described to use by a fpopen

Please reply without using hwiringpi, PX,L etc. I would like to use native code.


Greets, Wouter van Wegen

To get more response, this is the project photo:



It is because PXL does not compile on my brand new RPI4, and i want to shift over to native code from here to control upcomming problems...

[ojz0r]

Why do you want to use fpsystem call instead of a concrete working example with fpopen?

[ccrause]

I've recently started testing the IOCTL native interface, see e.g. this discussion on why it is supposed to be a "better" alternative.  A simple demo using gpio.pas.

[MarkMLl]

I've recently started testing the IOCTL native interface, see e.g. this discussion on why it is supposed to be a "better" alternative.  A simple demo using gpio.pas.

Thread at https://forum.lazarus.freepascal.org/index.php/topic,56063.msg416733.html#msg416733 applies.

It's better than going through the /sys/class etc. tree, but when I looked at it the API was far from stable.

*HOWEVER* it's applicable to more than just RPi, and I consider that to be an important consideration.

MarkMLl